The invention relates to a ball cock assembly of the type used for the control of liquid levels in tanks. More specifically, the invention relates to an improved float assembly for a ball cock assembly for controlling water level in a flush tank of a toilet.
A typical ball cock assembly, such as used in the flush tank of a toilet, includes a riser (or standpipe) connected to the water supply and a float-operated shutoff valve that controls the level of water in the flush tank. In a typical flush cycle, when the tank is flushed, a flush valve at the bottom of the tank opens and water empties (drains) rapidly from the tank. The float drops (descends) and the shutoff valve opens, allowing water to flow into the tank (meanwhile, the flush valve becomes closed). As the water level in the tank rises, the float rises until, at a given level, the shutoff valve closes. Then the tank is ready for another flush cycle. A typical ball cock assembly also includes means for preventing back flow of water from the flush tank to the supply line in the event of a total or substantial drop in the pressure of the incoming water.
Toilet flush tanks have different dimensions, particularly heights, which requires using risers of different heights. Examples of ball cock assemblies including an adjustable-height riser having telescopically adjustable concentric inlet and outlet tubes can be found in U.S. Pat. No. 4,100,928, U.S. Pat. No. 4,108,202, and U.S. Pat. No. 4,182,364, each of which is incorporated in its entirety by reference herein.
An exemplary float-controlled ball cock assembly is shown in commonly-owned U.S. Pat. No. 5,904,176, entitled SILENT VALVE BALL COCK ASSEMBLY, which is incorporated in its entirety by reference herein.
A number of float assemblies are known for use with risers, including adjustable risers. The float itself may be as simple as a buoyant element such as a watertight (air-filled) ball at the end of an elongate arm extending in a cantilever manner (e.g., generally horizontally) from the shutoff valve. The water level at which the shutoff valve will close can be adjusted simply by bending the elongate arm. It is also known to have an adjustment screw at the shutoff valve end of the elongate arm to effect water level adjustment. Setting a desired water level in the tank with such a float assembly is largely a process of trial and error, requiring repeated iterations of adjustment, flushing, waiting for the flush tank to fill and for the shutoff valve to shut, and examining the resulting water level.
In another type of float assembly, a buoyant element, such as a watertight donut (torus) is disposed around the standpipe and is connected via a substantially vertical connecting rod to an end of an the shutoff valve actuating arm (lever) extending from the shutoff valve. Another example of a float valve assembly may be found in U.S. Pat. No. 4,703,653 which is incorporated in its entirety by reference herein.
It is desirable that the water level in a flush tank can easily and precisely be adjusted. It is therefore inherently desirable that float assembly operate in a manner which can repeatedly cause the shutoff valve to close when a given (pre-selected) water level is attained in the flush tank. It is also desirable that a float assembly be inexpensive to manufacture, and easy to replace. It is also desirable that a replacement float assembly can be easily and precisely adjusted.
It is an object of the present invention to provide a ball cock assembly as defined in one or more of the appended claims and, as such having the capability of being constructed to accomplish one or more of the following subsidiary objects.
One object of the present invention is to provide a novel float assembly for use with a ball cock assembly.
Another object is to provide an improved anti-siphoning feature in a ball cock assembly.
These and other objects, which will become evident upon a full reading of the description, are achieved in the manner to be more fully described by reference to the drawings and detailed discussion which follows.
According to the invention a float assembly for a ball cock assembly for a flush tank of a toilet comprises an inner float component which is a buoyant element operatively connected to a shutoff valve atop a standpipe supplying water to the tank.
The inner float component is disposed in an outer float component which is in the general form of a container disposed within the flush tank so that its top edge is at a selected water level.
In the tank-filling portion of a flush cycle, when the water rises to the selected level, the outer float component suddenly becomes filled with water, causing the inner float element to abruptly rise, shutting off the flow of water into the flush tank.
In this manner, the buoyant element is caused to rise at a rate which is greater than a rate at which the water is rising in the tank.
The bottom of the outer float component is provided with a one-way valve so that, at the beginning of a flush cycle, when the water level drops to below the outer float component, water can drain out of the outer float component. When the water level again rises, the one-way valve, which itself is buoyant, closes.
According to a feature of the invention, a connecting rod connecting the inner float component to a shutoff valve actuating arm is provided with two flat surfaces so that it may easily be installed and so that the position at which it links to the inner float component can easily be adjusted.
According to a feature of the invention, an anti-siphon valve is disposed in a bottom portion of the standpipe to prevent water from draining out of the flush tank if there is a loss of pressure in the line supplying water to the flush tank.